A randomized clinical trial represents a controlled experiment in which the investigator applies an intervention to a group of patients and subsequently observes its effect on 1 or more outcomes over time. In this article, we outline the key elements that need to be considered during the design phase of a surgical clinical trial (Box).

Inception of a clinical trial starts by formulating a well-thought-out research question that is stated in the form of a hypothesis that will be tested. Trials are best reserved for mature questions that are supported by existing literature and can address a well-defined knowledge gap. Issues of patient safety and ethics deserve a special consideration in surgical trials, since the invasive nature of the procedures tested or, inversely, the risk of withholding surgical treatment due to study protocol requirements may both be associated with patient harm. For this reason, assessing patient and clinician equipoise for the proposed research question is important,¹ as lack of such equipoise limits trial feasibility and adversely affects the implementation of results.